Iron or steel cooking utensils such as a frying pan or a griddle are used for heating food such as meat or fish. However, iron or steel it is difficult to control the temperature of iron or steel utensils, because iron or steel has high thermal conductivity (0.1 - 0.13 cal/cm..degree. C.sec) and low specific heat (about 0.1 cal/gr..degree. C), i.e. low heat capacity. Accordingly, it is difficult to heat slowly food such as meat or fish by using the iron or steel utensils.
As substitutes for iron or steel utensils (ironwares), ceramic utensils such as earthen wares have been proposed. Such earthen wares have low thermal conductivity (1.2 - 1.5 .times. 10.sup.-3 cal/cm..degree. C.sec) and high specific heat (about 0.25 cal/gr..degree. C), i.e. high heat content. However, such low thermal conductivity is a disadvantage of the earthen wares, and the earthen wares have another disadvantage that they are porous. The porosity thereof is 15 - 20%. Accordingly, on heating meat or fish on such ceramic plate, gravy sinks into the pores of the plate, i.e. the cooking utensil absorb the gravy to become smudged or discolored.
An object of the present invention is provide improved ceramic cooking utensils for use in heating meat, fish or other foods.